Some of my 11 speed parts are due for replacing, and figured I may as well upgrade to 12 if its easy....

So, my current setup is:
- Dura Ace hydraulic di2 1 button brake levers
- SWR671 di2 2 button bar end shifters
- Ultegra 11 di2 derailleurs
- Shimano 11 cranks
- 11 speed cassette
- 11 speed chain
- BT-DN110-1 battery
- 5 port junction near head tube (4 wires in from brakes/shifters, 1 wire down to 4 port junction at BB)
- 4 port junction at BB to accept 1 from 5 port, and 1 wire out to battery, 1 wire out to each derailleur)


If I just throw 12 speed derailleurs, cranks, chain and cassette on there, will everything work? Will the existing wires plug into the new derailleurs and work with my current battery? Any issue with the older SWR671 shifters working with 12 speed?

Thanks!!